1-5-nitroanthraquinone-sulfonic acid.



lNrrEn S'rnrns Patented April 12, 1904.

a'rnnr Fries.

ROBERT E. SCHMIDT, OF ELBERFELD, GERMANY, ASSIGNOR TO FARBEN- FABRIKEN OF ELBERFELD (30., 'OF NEW YORK, N. Y., A CORPORA- TION OF NEW YORK.

1-5-NITROANTHRAQUINONE-SULFONIC ACID.

SPECIFICATION forming part of Letters Patent No. 757,057, dated April 12, 1904. l

Application filed Iannary 12,1904. $erial No. 188,702. (No specimens.)

so n

My new process for producing this body consists in treating anthraquinone-alpha-sulfonic acid (see United States Letters Patent No. 743,664., dated November 10, 1903) with nitric acid or with other nitrating agents. The 1-5 and the 1-8 nitroanthraquinone-sulfonic acids are thus produced simultaneously, which can be readily separated from each 3 other owing to the different degrees of their solubility or that of their salts.

In order to carry out my invention practically, I can proceed as follows, the parts bei'ngby weight: Fifty parts of nitric acid (45% Baum) are introduced into a solution of one hundred parts of the potassium salt of anthraquinonealpha'monosulfonic acid in seven hundred and fifty parts of a ninety-six-per-cent. sulfuric acid while stirring. The temperature 4 rises during the operation. On further heating to 80 to 90 centigrade the new 1-5-nitroanthraquinone-sulfonic acid separates in the shape of crystals. It is then stirred at this temperature for about from six to eight hours. After cooling, the new sulfonic acid is filtered off on asbestos. It can be purified by a crystallization from water. Its alkaline salts can also be precipitated from the aqueous solution by the addition of common salt or of potassium chlorid. The new body thus ob- 5 tained represents in the shape of its potassium salt microscopic plates of sharp outlines soluble with difficulty in cold water. By reduc tion 1-amidoanthraquinone-5-sulfonic acid results. On being heated with an aqueous solution of monomethylamin it is transformed into the l-methylamidoanthraquinone 5 sulfonic acid. By further heating this body with methylamin to 150 to 160 centigrade sym. 1-5-dimethyldiamidoanthraquinone results.

Instead of nitrating in a. mixture of sulfuric acid and nitric acid the nitration can also be performed with concentrated or monohydrated nitric acid alone.

Having now described my invention and in 5 what manner the same is to be performed, what I claim as new, and desire to secure by Letters Patent, is

The herein-described new 15'nitroanthra quinone-sulfonic acid which in the shape of 7 the potassium salt forms microscopic plates of sharp outlines soluble with difficulty in cold water; being transformed into 1-5-amidoanthraquinone-sulfonic acid when treated with reducing agents,and being transformed into 1- 7 5 methylamidoanthraquinone 5 sulfonic acid upon treatment with an aqueous solution of methylamin; substantially as described.

In testimony whereof I have signed my name in the presence of two subscribing witnesses.

ROBERT E. SCHMIDT. Witnesses:

Or'ro KoNIe, I J. A. RITTERSHAUS. 

